Suction device

ABSTRACT

A suction device that holds a member by suction in a stable manner is provided. The suction device includes a columnar main body, a flat end face formed on the main body, a concave part formed in the end face, a fluid flow-forming supply paths for forming a fluid swirl flow in the concave part by discharging fluid into the concave part, the fluid swirl flow generating negative pressure that applies suction to a member, and a linear guide groove formed on the end surface along a direction in which the fluid discharged into the concave part flows out of the concave part.

TECHNICAL FIELD

The present invention pertains to a device that applies suction to amaterial under application of Bernoulli's principle.

BACKGROUND ART

Recently, a device has been developed for non-contact conveyance of aplate-like member, such as a semiconductor wafer or a glass substrate.For example, Patent Document 1 discloses a device for non-contactconveyance of a plate-like member under application of Bernoulli'sprinciple. The device includes a cylindrical chamber that opens to anunderside. Fluid is supplied into the chamber to generate a swirl flowhaving a central negative pressure, which exerts suction on theplate-like member. Fluid flowing out of the cylindrical chamber causes aset distance to be maintained between the device and the plate-likemember, thereby enabling non-contact conveyance of the plate-like memberby the device

PRIOR ART DOCUMENT Patent Document

Patent Document 1: JP 2005-51260 A1

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

The present invention has been made in view of this technology, and hasas its object the provision of a suction device that is able to hold amember under suction in a highly stable manner.

Means for Solving the Problems

To solve the problem described above, a suction device according to thepresent invention comprises: a cylindrical main body; an end face formedon the main body; a concave part formed in the end face; a fluidflow-forming means for forming a fluid swirl flow in the concave part orforming a radial flow by discharging fluid into the concave part, thefluid swirl flow or the radial flow generating negative pressure thatapplies suction to a member; and a linear guide groove formed on the endface along a direction in which the fluid discharged into the concavepart flows out of the concave part.

The fluid flow-forming means may be a fluid passage through which thefluid is discharged into the concave part to cause the fluid swirl flowto be formed, and the guide groove may be formed on the end face, whenviewed towards the end face, along a direction that forms an angle ofapproximately 45 degrees with respect to a direction in which the fluidpassage extends.

The fluid flow-forming means may be a fluid passage through which thefluid is discharged into the concave part to cause the radial flow to beformed, and the guide groove may be formed on the end face, when viewedtowards the end face, along a direction substantially parallel to adirection in which the fluid passage extends.

The guide groove may be formed such that a cross-sectional area of theguide groove increases in proportion to a distance from the concavepart.

The guide groove may be formed such that a cross-sectional area of theguide groove decreases in proportion to a distance from the concavepart.

The suction device may further comprise a movement restriction meansprovided on the end face, for restricting movement along the end face ofthe member to which suction is applied by the negative pressure.

The movement restriction means may be a horn-shaped protrusion thatrestricts movement of the member by piercing the member.

Another suction device according to the present invention comprises: acolumnar main body; an end face formed on the main body; a concave partformed in the end face; a fluid flow-forming means for forming a fluidswirl flow in the concave part or forming a radial flow by dischargingfluid into the concave part, the fluid swirl flow or the radial flowgenerating negative pressure that applies suction to a member; and alinear guide groove formed on the end face along a direction in whichthe fluid discharged into the concave part flows out of the concavepart, the guide groove having a smaller curvature than an arc of anopening edge of the concave part when viewed towards the end face.

Another suction device according to the present invention comprises: acolumnar main body; a concave part formed in a surface of the main body;a fluid flow-forming means for forming a fluid swirl flow in the concavepart or forming a radial flow by discharging fluid into the concavepart, the fluid swirl flow or the radial flow generating negativepressure that applies suction to a member; an annular wall, provided soas to surround the concave part, that prevents the member from enteringthe concave part; and a linear guide groove formed on an inner wallsurface of the annular wall along a direction in which the fluiddischarged into the concave part flows out of the concave part.

Another suction device according to the present invention comprises: acolumnar main body; a concave part formed in a surface of the main body;a fluid flow-forming means for forming a fluid swirl flow in the concavepart or forming a radial flow by discharging fluid into the concavepart, the fluid swirl flow or the radial flow generating negativepressure that applies suction to a member; an annular wall, provided soas to surround the concave part, that prevents the member from enteringthe concave part; and a linear guide groove formed on an inner wallsurface of the annular wall along a direction in which the fluiddischarged into the concave part flows out of the concave part, theguide groove having a smaller curvature than an arc of an opening edgeof the concave part when viewed towards the opening edge of the concavepart.

EFFECTS OF THE INVENTION

The suction device according to the present invention is able to morestably hold a member under suction than a suction device that does notinclude a guide groove.

FIG. 1 is a perspective view of an example of swirl flow-forming body 1.

FIG. 2 is a bottom view of an example of swirl flow-forming body 1.

FIG. 3 is a cross-sectional view of swirl flow-forming body 1 along lineA-A shown in FIG. 2 .

FIG. 4 is a cross-sectional view of swirl flow-forming body 1 along lineB-B shown in FIG. 3 .

FIG. 5 is a diagram showing an example of arrangement of guide grooves16.

FIG. 6 is a perspective view of an example of swirl flow-forming body 2.

FIG. 7 is a bottom view of an example of swirl flow-forming body 2.

FIG. 8 is a diagram showing an example arrangement of guide grooves 22.

FIG. 9 is a perspective view of an example of radial flow-forming body3.

FIG. 10 is a bottom view of an example of radial flow-forming body 3.

FIG. 11 is a cross-sectional view of radial flow-forming body 3 alongline C-C shown in FIG. 10 .

FIG. 12 is a diagram showing an example arrangement of guide grooves 36.

FIG. 13 is a perspective view of an example of radial flow-forming body4.

FIG. 14 is a bottom view of an example of radial flow-forming body 4.

FIG. 15 is a diagram showing an example arrangement of guide grooves 43.

FIG. 16 is a perspective view of a modification of guide grooves 16.

FIG. 17 is a bottom view of a modification of guide grooves 16.

FIG. 18 is a perspective view of a modification of guide grooves 16.

FIG. 19 is a bottom view of a modification of guide grooves 16.

FIG. 20 is a perspective view of a modification of guide grooves 16.

FIG. 21 is a bottom view of a modification of guide grooves 16.

FIG. 22 is a perspective view of a modification of guide grooves 36.

FIG. 23 is a bottom view of a modification of guide grooves 36.

FIG. 24 is a perspective view of a modification of guide grooves 36.

FIG. 25 is a bottom view of a modification of guide grooves 36.

FIG. 26 is a perspective view of a modification of guide grooves 36.

FIG. 27 is a bottom view of a modification of guide grooves 36.

FIG. 28 is a side view of a modification of guide grooves.

FIG. 29 is a perspective view of an example of swirl flow-forming body1A.

FIG. 30 is a bottom view of an example of swirl flow-forming body 1A.

FIG. 31 is a side view of an example of swirl flow-forming body 1B.

FIG. 32 is a side view of an example of swirl flow-forming body 1C.

MODES FOR IMPLEMENTING THE INVENTION

Embodiments of the present invention are described below with referenceto the figures.

1. First Embodiment

FIG. 1 shows a perspective view of an example of swirl flow-forming body1, which is an example of a “suction device” according to the presentinvention. FIG. 2 shows a bottom view of an example of swirlflow-forming body 1. FIG. 3 shows a cross-sectional view of swirlflow-forming body 1 along line A-A shown in FIG. 2 . FIG. 4 shows across-sectional view of swirl flow-forming body 1 along line B-B shownin FIG. 3 . Swirl flow-forming body 1 shown in these drawings is adevice for forming a swirl flow, formation of which causes suction to beapplied to a member under application of Bernoulli's principle. Themember to which suction is applied by swirl flow-forming body 1 may be,for example, a food such as a croquette or a Japanese deep-fried dish.Swirl flow-forming body 1 may be attached to an end of a robot arm, forexample.

Swirl flow-forming body 1 includes main body 11, end face 12, concavepart 13, two jetting ports 14, inclined surface 15, and eight guidegrooves 16. Main body 11 is made from an aluminum alloy and iscylindrical in shape. End face 12 is formed in a flat shape on a surfaceof main body 11, which is to face a member to be conveyed. Hereafter,the surface of main body 11 is simply referred to as a “bottom surface.”Concave part 13 is a column-shaped bottomed hole and is formed on endface 13. Concave part 13 is formed on the same axis as main body 11. Twojetting ports 14 are formed on inner-peripheral side surface 111 of mainbody 11 facing concave part 13. Jetting ports 14 are arranged nearer endface 12 in relation to the center in the axial direction ofinner-peripheral side surface 111. Jetting ports 14 are arranged inmutually opposing relation to each other. Specifically, jetting ports 14are arranged in point symmetry about the axial center of the centralaxis of main body 11 or concave part 13. Jetting ports 14 allow fluidsupplied to swirl flow-forming body 1 to be discharged into concave part13. The fluid discharged into concave part 13 may be, for example, a gassuch as compressed air, or a liquid such as pure water or carbonatedwater. Inclined surface 15 is formed at the opening end of main body 11.

Eight guide grooves 16 are formed in a straight line from the innerperipheral edge to the outer peripheral edge of end face 12 along adirection in which fluid discharged into concave part 13 flows out ofconcave part 13. The direction in which the fluid flows out of concavepart 13 refers to, specifically, a direction of a vector obtained bycombining vectors of fluid molecules that are discharged from jettingport 14 and flow out of concave part 13. More specifically, guide groove16 is formed, when viewed towards end face 12, along a direction thatforms an angle of approximately 36 degrees with respect to a tangentline that passes through the contact point between the guide groove 16and the opening edge of concave part 13. For example, on the exemplarybottom shown in FIG. 5 , a direction of guide groove 16A forms an angleof 36 degrees with respect to tangent line L1 that passes throughcontact point P1 between the guide groove 16A and the opening edge ofconcave part 13. Among eight guide grooves 16, a direction of two guidegrooves 16, when viewed towards end face 12, forms an angle ofapproximately 45 degrees with respect to a direction in which supplypath 20 (described later) extends. The other six guide grooves 16 areformed such that adjacent guide grooves 16 extend in directions thatform an angle of approximately 45 degrees. For example, on the exemplarybottom shown in FIG. 5 , a direction of guide groove 16B (arrow A2)forms an angle of 45 degrees with respect to a direction (arrow A1) inwhich supply path 20A extends. A direction of guide groove 16C (arrowA4) forms an angle of 45 degrees with respect to a direction (arrow A3)in which supply path 20B extends. Each of the guide grooves 16 has asemicircular cross-sectional shape.

The guide grooves 16 configured as described in the foregoing align andguide most of the fluid molecules flowing out from the opening ofconcave part 13, in a direction away from concave part 13. A collisionrate of the fluid molecules guided by the guide grooves 16 with themember conveyed is lower than that of fluid molecules flowing along endface 12.

Swirl flow-forming body 1 also includes supply port 17, annular passage18, communication passage 19, and two supply paths 20, which is anexample of “fluid flow-forming means” according to the presentinvention. Supply port 17 has a disk shape and is provided in the centerof the top surface (that is, the surface opposite the bottom surface) ofmain body 11. Supply port 17 is connected to a fluid supply pump (notillustrated) via a tube, for example. Fluid is supplied into main body11 via supply port 17. Annular passage 18 has a cylindrical shape and isformed inside main body 11 so as to surround concave part 13. Annularpassage 18 is formed on the same axis as concave part 13. Annularpassage 18 supplies supply path 20 with fluid supplied fromcommunication passage 19. Communication passage 19 is provided insidemain body 11 and extends in a straight line in a radial direction of thebottom surface or top surface of main body 11. Both ends ofcommunication passage 19 are in communication with annular passage 18.Communication passage 19 supplies annular passage 18 with fluid that issupplied into main body 11 via supply port 17. Two supply paths 20 areformed approximately parallel to end face 12, and extend in a directiontangential to the outer periphery of concave part 13, and are parallelto each other. Each of supply paths 20 communicates with annular passage18 at one end, and communicates with jetting port 14 at the other endthereof. Each of supply paths 20 forms a fluid swirl flow within concavepart 13.

A suction operation of swirl flow-forming body 1 is described below.When swirl flow-forming body 1 is supplied with fluid from the fluidsupply pump via supply port 17, the fluid passes through each ofcommunication passage 19, annular passage 18, and supply paths 20 fordischarge from jetting ports 14 into concave part 13. Upon discharge ofthe fluid a swirl flow is created within concave part 13, and the fluidsubsequently flows out of the opening of concave part 13. If a member tobe conveyed is present in a position opposing the opening of concavepart 13, inflow of external fluid to concave part 13 is restricted, anda density of fluid molecules per unit volume in the center of the swirlflow is reduced under the action of centrifugal force and an entrainmenteffect of the swirl flow; in other words, a negative pressure isgenerated within concave part 13. As a result, fluid that surroundsswirl flow-forming body 1 is caused to flow into concave part 13, sothat pressure is applied to the member by the surrounding fluid to begravitated towards swirl flow-forming body 1. On the other hand, mostfluid molecules flowing out of the opening of concave part 13 arealigned and discharged out of swirl flow-forming body 1 by guide grooves16.

According to swirl flow-forming body 1, most fluid molecules flowing outof concave part 13 are aligned and discharged by guide grooves 16, sothat the fluid molecules are prevented from colliding with the member.As a result, undulation and rotation of the member is controlled, andnoise caused by collision between the fluid molecules and the member isreduced. Swirl flow-forming body 1 has fewer parts than a conventionalsuction device in which spacers inserted between a swirl flow-formingbody and a baffle plate form flow paths of outflow fluid (for example,refer to published unexamined patent application No. 2016-159405), sothat swirl flow-forming body 1 can be manufactured at a lower cost. Itis easier to clean flow paths of swirl flow-forming body 1 than to cleanthose of a conventional suction device in which the baffle plate coversthe flow paths.

According to swirl flow-forming body 1, all fluid to which suction isapplied by swirl flow-forming body 1 is discharged out of swirlflow-forming body 1, and does not enter concave part 13 or jetting port14, whereby the supply path of fluid is prevented from beingcontaminated by the member.

2. Second Embodiment

Swirl flow-forming body 2 according to a second embodiment, which is anexample of a “suction device” according to the present invention,differs from swirl flow-forming body 1 according to the first embodimentin that swirl flow-forming body 2 includes annular wall 21 on whicheight guide grooves 22 are formed, instead of end face 12 and inclinedsurface 15. Below, this difference is described.

FIG. 6 shows a perspective view of an example of swirl flow-forming body2. FIG. 7 shows a bottom view of an example of swirl flow-forming body2. Annular wall 21 shown in these drawings has a trapezoidalcross-sectional shape. Annular wall 21 is formed such that: the outerdiameter of one end face is equal to the diameter of main body 11 andthe inner diameter of the one end face is equal to the diameter ofconcave part 13; and the outer diameter of the other end face is smallerthan the outer diameter of the one end face, and the inner diameter ofthe other end face is larger than the inner diameter of the one endface. In other words, annular wall 21 is formed such that a thickness(or an opening area) of annular wall 21 gradually decreases from one endto the other end. The one end face of annular wall 21 is fixed to mainbody 11 on the same axis as main body 11 so as to surround concave part13.

Annular wall 21 configured as described in the foregoing comes intocontact with a member to which suction is applied by negative pressuregenerated in concave part 13, so that the member is prevented fromentering concave part 13. Annular wall 21 also prevents the member, apart of which has entered the opening of annual wall 21, from moving ina radial direction.

Eight guide grooves 22 are formed in a straight line from the one end tothe other end of annular wall 21 along a direction in which fluiddischarged into concave part 13 flows out of concave part 13. Thedirection in which the fluid flows out of concave part 13 refers to,specifically, a direction of a vector obtained by combining vectors offluid molecules that are discharged from jetting port 14 and flow out ofconcave part 13. More specifically, guide groove 22 is formed, whenviewed towards the other end of annular wall 21, along a direction thatforms an angle of approximately 20 degrees with respect to a tangentline that passes through the contact point between the guide groove 22and the opening edge of concave part 13. For example, on the exemplarybottom shown in FIG. 8 , a direction of guide groove 22A forms an angleof 20 degrees with respect to tangent line L2 that passes throughcontact point P2 between the guide groove 22A and the opening edge ofconcave part 13. Among eight guide grooves 22, a direction of two guidegrooves 22, when viewed towards the other end of annular wall 21, formsan angle of approximately 45 degrees with respect to a direction inwhich supply path 20 extends. The other six guide grooves 22 are formedsuch that directions of adjacent guide grooves 22 form an angle ofapproximately 45 degrees. For example, on the exemplary bottom shown inFIG. 8 , a direction of guide groove 22B (arrow A4) forms an angle of 45degrees with respect to a direction (arrow A1) in which supply path 20Aextends. A direction of guide groove 22C (arrow A5) forms an angle of 45degrees with respect to a direction (arrow A3) in which supply path 20Bextends. Each of the guide grooves 22 has a semicircular cross-sectionalshape.

The guide grooves 22 configured as described in the foregoing align andguide most of the fluid molecules flowing out from the opening ofconcave part 13, in a direction away from concave part 13. A collisionrate of the fluid molecules guided by the guide grooves 22 with themember conveyed is lower than that of fluid molecules flowing along theinner wall surface of annular wall 21.

According to swirl flow-forming body 2, during a suction operation, mostof the fluid molecules flowing out of concave part 13 are aligned anddischarged out of swirl flow-forming body 2 by guide grooves 22.Accordingly, swirl flow-forming body 2 has the same effect as swirlflow-forming body 1 according to the first embodiment.

3. Third Embodiment

Radial flow-forming body 3 according to a third embodiment, which is anexample of a “suction device” according to the present invention,differs from swirl flow-forming body 1 according to the first embodimentin that radial flow-forming body 3 forms a radial flow that appliessuction to a member by use of Bernoulli's principle. Below, thedifference is described.

FIG. 9 shows a perspective view of an example of radial flow-formingbody 3. FIG. 10 is a bottom view of an example of radial flow-formingbody 3. FIG. 11 shows a cross-sectional view of radial flow-forming body3 along line C-C shown in FIG. 10 . Radial flow-forming body 3 shown inthese drawings includes main body 31, annular concave part 32, end face33, opposing surface 34, inclined surface 35, and eight guide grooves36. Main body 31 is made from an aluminum alloy and is cylindrical. Endface 33 is formed in a flat shape on a surface of main body 31 thatdeals with a member to be conveyed. The surface of main body 31 ishereafter referred to as “bottom surface.” Annular concave part 32 isformed on end face 33 concentrically with the outer periphery of mainbody 31. Opposing surface 34 formed on the bottom surface of main body31 is flat, whereby opposing surface 34 is recessed relative to end face33. Opposing surface 34 is surrounded by annular concave part 32 andfaces a member to be conveyed. Inclined surface 35 is formed on theopening end of annular concave part 32.

Eight guide grooves 36 are formed in a straight line from the innerperipheral edge to the outer peripheral edge of end face 33 along adirection in which fluid discharged into annular concave part 32 flowsout of annular concave part 32. The direction in which the fluid flowsout of annular concave part 32 refers to, specifically, a direction of avector obtained by combining vectors of fluid molecules that aredischarged from nozzle passage 37 (described later) and flow out ofannular concave part 32. More specifically, a direction of guide groove36, when viewed towards end face 33, forms an angle of approximately 90degrees with respect to a tangent line that passes through the contactpoint between the guide groove 36 and the opening edge of annularconcave part 32. For example, on the exemplary bottom shown in FIG. 12 ,a direction of guide groove 36A forms an angle of 90 degrees withrespect to tangent line L3 that passes through contact point P3 betweenthe guide groove 36A and the opening edge of annular concave part 32. Adirection of guide groove 36, when viewed towards end face 33, issubstantially parallel to a direction in which nozzle passage 37 extends(more specifically, in a straight line). For example, on the exemplarybottom shown in FIG. 12 , guide groove 36B is formed along a direction(arrow A6) in which nozzle passage 37A extends.

The guide grooves 36 configured as described in the foregoing align andguide most of the fluid molecules flowing out from the opening ofannular concave part 32, in a direction away from annular concave part32. A collision rate of the fluid molecules guided by the guide grooves36 with the member conveyed is lower than that of fluid moleculesflowing along end face 33.

Radial flow-forming body 3 also includes eight nozzle passages 37, whichare examples of a “fluid flow-forming means” according to the presentinvention, introduction port 38, introduction path 39, annular passage40, and communication passage 41. Introduction port 38 has a circularshape and is provided in the center of the top surface (that is, thesurface opposite the bottom surface) of main body 31. Introduction port38 is connected to a fluid supply pump (not illustrated), via a tube,for example. Introduction path 39 is provided inside main body 31, andextends in a straight line along the central axis of main body 31.Introduction path 39 communicates with introduction port 38 at one end,and communicates with communication passage 41 at the other end thereof.Introduction path 39 supplies communication passage 41 with fluidsupplied into main body 31 via introduction port 38.

Communication passage 41 is provided inside main body 31, and extends ina straight line in the radial direction of annular passage 40.Communication passage 41 communicates with introduction path 39 at thecentral part thereof in the axial direction, and communicates withannular passage 40 at both ends thereof. Communication passage 41supplies annular passage 40 with fluid supplied from introduction path39. Annular passage 40 has a cylindrical shape and is provided insidemain body 31. Annular passage 40 is formed on the same axis as main body31. Annular passage 40 supplies nozzle passages 37 with fluid suppliedfrom communication passage 41.

Each of the eight nozzle passages 37 is formed so as to be approximatelyparallel to end face 33 or opposing surface 34 and to extend in astraight line in the radial direction of the bottom surface or topsurface of main body 31, one end thereof communicating with annularpassage 40 and the other end communicating with annular concave part 32.The nozzle passages 37 are arranged on the same plane such that adjacenttwo nozzle passages 37 form an angle of approximately 45 degrees. Eachof the nozzle passages 37 discharges fluid into annular concave part 32to form a radial flow.

A suction operation of radial flow-forming body 3 is described below.When radial flow-forming body 3 is supplied with fluid via introductionport 38, the fluid passes through introduction path 39, communicationpassage 41, and annular passage 40 to be discharged from nozzle passages37 into annular concave part 32. The fluid discharged into annularconcave part 32 flows out of the opening of annular concave part 32 as aradial flow. At this time, if a member to be conveyed is present in aposition opposing the opening of annular concave part 32, inflow ofexternal fluid to the space between radial flow-forming body 3 and themember is limited, and the density of fluid molecules per unit volume inthe space becomes reduced due to an entrainment effect of the radialflow; in other words, negative pressure is generated. As a result,pressure is applied to the member by the surrounding fluid to begravitated towards radial flow-forming body 3. On the other hand, mostof the fluid molecules flowing out of the opening of annular concavepart 32 are aligned and discharged out of radial flow-forming body 3 byguide grooves 36.

According to radial flow-forming body 3, most of the fluid moleculesflowing out of annular concave part 32 are aligned and discharged byguide grooves 36, so that the fluid molecules are prevented fromcolliding with the member. As a result, undulation and rotation of themember is controlled, and a noise caused by collision between the fluidmolecules and the member is reduced. Radial flow-forming body 3 hasfewer parts than the above-described conventional suction device;therefore, radial flow-forming body 3 can be manufactured at a lowercost. It is easier to clean flow paths of radial flow-forming body 3than to clean those of a conventional suction device in which the baffleplate covers the flow paths.

According to radial flow-forming body 3, all fluid to which suction isapplied by radial flow-forming body 3 is discharged out of radialflow-forming body 3, and does not enter annular concave part 32 ornozzle passage 37, whereby the supply path of fluid is prevented frombeing contaminated by the member.

4. Fourth Embodiment

Radial flow-forming body 4 according to a fourth embodiment, which is anexample of a “suction device” according to the present invention,differs from radial flow-forming body 3 according to the thirdembodiment in that radial flow-forming body 4 includes annular wall 42on which eight guide grooves 43 are formed, instead of end face 33.Below, the difference is described.

FIG. 13 shows a perspective view of an example of radial flow-formingbody 4. FIG. 14 shows a bottom view of an example of radial flow-formingbody 4. Annular wall 42 shown in these drawings has a trapezoidalcross-sectional shape. Annular wall 42 is formed such that: the outerdiameter of one end face is equal to the diameter of main body 31 andthe inner diameter of the one end face is equal to the outer diameter ofannular concave part 32; and the outer diameter of the other end face issmaller than the outer diameter of the one end face, and the innerdiameter of the other end face is larger than the inner diameter of theone end face. In other words, annular wall 42 is formed such that athickness (or an opening area) of annular wall 42 gradually decreasesfrom one end to the other end. The one end face of annular wall 42 isfixed to main body 31 on the same axis as main body 31 so as to surroundannular concave part 32.

Annular wall 42 configured as described in the foregoing comes intocontact with a member to which suction is applied by negative pressuregenerated by main body 31, so that the member is prevented from enteringannular concave part 32. Annular wall 42 also prevents the member, apart of which has entered the opening of annual wall 42, from moving ina radial direction.

Eight guide grooves 43 are formed in a straight line from the one end tothe other end of annular wall 42 along a direction in which fluiddischarged into annular concave part 32 flows out of annular concavepart 32. The direction in which the fluid flows out of annular concavepart 32 refers to, specifically, a direction of a vector obtained bycombining vectors of fluid molecules that are discharged from nozzlepassage 37 and flow out of annular concave part 32. More specifically, adirection of guide groove 43, when viewed towards the other end ofannular wall 42, forms an angle of approximately 90 degrees with respectto a tangent line that passes through the contact point between theguide groove 43 and the opening edge of annular concave part 32. Forexample, on the exemplary bottom shown in FIG. 15 , a direction of guidegroove 43A forms an angle of 90 degrees with respect to tangent line L4that passes through contact point P4 between the guide groove 43A andthe opening edge of annular concave part 32. A direction of guide groove43, when viewed towards the other end of annular wall 42, issubstantially parallel to a direction in which nozzle passage 37 extends(more specifically, a straight line). For example, on the exemplarybottom shown in FIG. 15 , guide groove 43B is formed along a direction(arrow A6) in which nozzle passage 37A extends.

The guide grooves 43 configured as described in the foregoing align andguide most of the fluid molecules flowing out from the opening ofannular concave part 32, in a direction away from annular concave part32. A collision rate of the fluid molecules guided by the guide grooves43 with the member conveyed is lower than that of fluid moleculesflowing along the inner wall surface of annular wall 43.

According to radial flow-forming body 4, during a suction operation,most of the fluid molecules flowing out of annular concave part 32 arealigned and discharged out of radial flow-forming body 4 by guidegrooves 43. Accordingly, radial flow-forming body 4 has the same effectas radial flow-forming body 3 according to the third embodiment.

5. Modifications

The embodiments described above may be modified as described below. Itis of note that the following modifications may be combined.

5-1. Modification 1

The shape of main body 11 and concave part 13 of swirl flow-forming body1 according to the first embodiment is not limited to a cylindricalshape, and may be a square or elliptical columnar shape.Inner-peripheral side surface 111 of main body 11 that faces concavepart 13 may be tapered such that the diameter of concave part 13enlarges toward the opening. Swirl flow-forming body 1 may be providedwith a convex part that is formed within concave part 13 such that afluid flow path is formed between the outer-peripheral side surface ofthe convex part and inner-peripheral side surface 111 of main body 11(for example, refer to FIG. 13 of published unexamined patentapplication number 2016-159405). The number of jetting ports 14 andsupply paths 20 provided in swirl flow-forming body 1 is not limited totwo, and may be fewer or may be more. Jetting ports 14 may be arrangedin any of an upper side, at the center, or in a lower side in the axialdirection of inner-peripheral side surface 111. The formation ofinclined surface 15 may be omitted. The shape of supply port 17 is notlimited to being circular, and may be rectangular or elliptical. Supplyport 17 may be formed on the side surface of main body 11, instead of onthe top surface. Supply paths 20 do not necessarily have to be parallelto each other.

In swirl flow-forming body 1 according to the first embodiment, anelectric fan for forming a swirl flow that applies suction to a memberby use of Bernoulli's principle may be adopted, instead of the fluidpassages formed inside main body 11 (for example, refer to publishedunexamined patent application number 2011-138948). The electric fan isan example of a “fluid flow-forming body” according to the presentinvention.

The shape of main body 31 of radial flow-forming body 3 according to thethird embodiment is not limited to being cylindrical, and may be asquare or elliptical columnar shape. The number of nozzle passages 37provided in radial flow-forming body 3 is not limited to eight, and maybe fewer or may be more. The shape of introduction port 38 is notlimited to being circular, and may be rectangular or elliptical.Introduction port 38 may be formed on the side surface of main body 31,instead of on the top surface.

The cross-sectional shapes of annular walls 21 according to the secondembodiment and annular wall 42 according to the fourth embodiment arenot limited to being trapezoid, but may be a semicircular or triangularshape. Annular wall 21 and main body 11 may be integrally formed, andannular wall 42 and main body 31 may be integrally formed.

5-2. Modification 2

FIGS. 16 to 21 are diagrams showing modifications of guide grooves 16according to the first embodiment. FIGS. 16 and 17 show guide grooves 51that differ from guide grooves 16 in that the cross-sectional shape ofguide grooves 51 is rectangular. It is of note that the cross-sectionalshape of guide grooves 51 may be a V shape or a semi-elliptical shape.FIGS. 18 and 19 show guide grooves 52 that differ from guide grooves 16in that the cross-sectional shape of guide grooves 52 is rectangular,and that the cross-sectional area of guide grooves 52 increases inproportion to the distance from concave part 13. It is of note thatguide grooves 52 may have a width that increases in proportion to thedistance from concave part 13, and/or a depth that increases inproportion to the distance from concave part 13. FIGS. 20 and 21 showguide grooves 53 that differ from guide grooves 16 in that thecross-sectional shape of guide grooves 53 is rectangular, and that thecross-sectional area of guide grooves 53 decreases in proportion to thedistance from concave part 13. It is of note that guide grooves 53 mayhave a width that decreases in proportion to the distance from concavepart 13, and/or a depth that decreases in proportion to the distancefrom concave part 13.

It is of note that each of the modifications to guide grooves 16 may beapplied to guide grooves 22 according to the second embodiment.

FIGS. 22 to 27 are diagrams showing modifications of guide grooves 36according to the third embodiment. FIGS. 22 and 23 show guide grooves 61that differ from guide grooves 36 in that the cross-sectional shape ofguide grooves 61 is rectangular. It is of note that the cross-sectionalshape of guide grooves 61 may be a V shape or a semi-elliptical shape.FIGS. 24 and 25 show guide grooves 62 that differ from guide grooves 36in that the cross-sectional shape of guide grooves 62 is rectangular,and that the cross-sectional area of guide grooves 62 increases inproportion to the distance from annular concave part 32. It is of notethat guide grooves 62 may have a width that increases in proportion tothe distance from annular concave part 32, and/or a depth that increasesin proportion to the distance from annular concave part 32. FIGS. 26 and27 show guide grooves 63 that differ from guide grooves 36 in that thecross-sectional shape of guide grooves 63 is rectangular, and that thecross-sectional area of guide grooves 63 decreases in proportion to thedistance from annular concave part 32. It is of note that guide grooves63 may have a width that decreases in proportion to the distance fromannular concave part 32, and/or a depth that decreases in proportion tothe distance from annular concave part 32.

It is of note that each of the modifications to guide grooves 36 may beapplied to guide grooves 43 according to the fourth embodiment.

The number of guide grooves according to each of the above embodimentsis not limited to eight, and may be fewer or may be more. A width and adepth of each of the guide grooves may be larger than is shown in theillustrated example. For example, end face 12 according to the firstembodiment may be a corrugated surface in a side view, as shown in FIG.28 . An arrangement of the guide grooves is not limited to the aboveexamples. An optimum number, size, and arrangement of the guide groovesare determined based on the flow amount of fluid flowing out from theconcave part.

Guide grooves according to each of the above embodiments are notnecessarily limited to being linear, and may be slightly curved.Specifically, the guide grooves may have a smaller curvature than thatof an arc of the opening edge of the concave part or an arc of the outerperiphery of the main body when viewed towards the end face or theconcave part of the main body. For example, the guide grooves may havehalf the curvature of an arc of the opening edge of the concave part oran arc of the outer periphery of the main body. In a case that the mainbody has a square columnar shape, the guide grooves may have a smallercurvature than that of an arc of a circumscribed circle that passesthrough the apexes on the outer side of the main body when viewedtowards the end face or the concave part of the main body.

5-3. Modification 3

On end face 12 of swirl flow-forming body 1 according to the firstembodiment, protrusions 71 may be provided to prevent lateraldisplacement of a conveyed member. The protrusions 71 are examples of a“movement restriction means” according to the present invention. FIG. 29shows a perspective view of an example of swirl flow-forming body 1A,which is an example of a “suction device” according to the presentinvention. FIG. 30 shows a bottom view of an example of swirlflow-forming body 1A. Four protrusions 71 shown in these drawings have acylindrical shape with a sharp tip, and are attached to end face 12 suchthat the protrusions 71 extend substantially vertically from end face12. The protrusions 71 are arranged so as to surround a member to whichsuction is applied by negative pressure. The protrusions 71 shown in thedrawings are arranged at equal intervals in the center in the radialdirection of end face 12. The protrusions 71 thus configured prevent amember to which suction is applied by negative pressure from movingalong end face 12 during high-speed conveyance.

The shape of the protrusions 71 may be a square columnar shape with asharp tip, or a cone or pyramid shape. The number of the protrusions 71may be fewer than three, or more than five. The protrusions 71 may bearranged at the outer or inner edge in the radial direction of end face12. The protrusions 71 may be arranged so as to pierce a member to whichsuction is applied by negative pressure.

The protrusions 71 may be attached to end face 33 of radial flow-formingbody 3 according to the third embodiment.

5-4. Modification 4

FIG. 31 shows a side view of an example of swirl flow-forming body 1B,which is a modification of swirl flow-forming body 1A according tomodification 3. Swirl flow-forming body 1B shown in the drawing differsfrom swirl flow-forming body 1A in that swirl flow-forming body 1B lackseight guide grooves 16, and that swirl flow-forming body 1B includes theprotrusions 71 that are attached to end face 12 via spacer 81. The fourspacers 81 provided in swirl flow-forming body 1B are cylindrical andhave a diameter larger than that of protrusion 71, and are attached toend face 12 on the same axis as protrusion 71. It is of note that shapeof the spacers 81 may be modified to a square columnar shape. Thespacers 81, when swirl flow-forming body 1B conveys a member such as aJapanese deep-fried dish while the member is pierced by the protrusions71, come into contact with a surface of the member, so that the memberis prevented from coming into contact with end face 12. Accordingly, agap is maintained between the member and end face 12. This gap enablesoutflow of most of the fluid molecules flowing out from the opening ofconcave part 13, whereby a rate of collision between the outflow fluidand the member is reduced. For these reasons, swirl flow-forming body 1Bhas the same effect as swirl flow-forming body 1 according to the firstembodiment.

5-5. Modification 5

On end face 12 of swirl flow-forming body 1 according to the firstembodiment, cylindrical body 91 may be attached to hold a conveyedmember. FIG. 32 is a side view of an example of swirl flow-forming body1C including cylindrical body 91, which is an example of a “suctiondevice” according to the present invention. Cylindrical body 91 shown inthe drawing is a bellows-shaped cylindrical body made of an elasticmaterial such as rubber, and is a member for holding a member to whichsuction is applied by swirl flow-forming body 1C. An end of cylindricalbody 91 is fixed on end face 12 such that cylindrical body 91 allowspassage of fluid to which suction is applied by negative pressuregenerated by swirl flow-forming body 1C, and also prevents a conveyedmember from entering concave part 13. Specifically, cylindrical body 91is fixed on end face 12 on the same axis as concave part 13. Cylindricalbody 91 has constricted parts whose inner diameter is smaller than theinner diameter of concave part 13 and the maximum diameter of a conveyedmember. Another end of cylindrical body 91 is expanded toward a conveyedmember. The height of cylindrical body 91 is determined based on theflow amount of fluid supplied from the fluid supply pump to swirlflow-forming body 1C, and on a type of a member to be conveyed. It is ofnote that the shape of cylindrical body 91 is not limited to beingcylindrical, and may be a square or elliptical columnar shape.

According to swirl flow-forming body 1C, cylindrical body 91 restrictsinflow of surrounding fluid into swirl flow-forming body 1C applyingsuction to a member, so that swirl flow-forming body 1C can applysuction to the member positioned away from the negative pressuregeneration area. The bellows shape of cylindrical body 91 enablescylindrical body 91 to deform according to a shape of a conveyed member;accordingly, in a case where a misalignment occurs between swirlflow-forming body 1C and a conveyed member, swirl flow-forming body 1Ccan hold the member stably. Also, due to its bellows shape, cylindricalbody 91 causes less damage to a conveyed member in the event of contactwith the conveyed member. Also, due to the bellows shape of cylindricalbody 91, it is easier to secure a vertical clearance between swirlflow-forming body 1C and a conveyed member, because expansion andcontraction of cylindrical body 91 compensate for variations in heightof members to conveyed. Cylindrical body 91 may have constricted partswhose inner diameter is smaller than or equal to one-half of the innerdiameter of concave part 13 of swirl flow-forming body 1C, so that swirlflow-forming body 1C can convey a smaller member.

Cylindrical body 91 may have notches that are formed at an end ofcylindrical body 91 at which a conveyed member is held. The shape of thenotches may include a sawtooth shape, and a semicircle, semi-oval, orrectangle shape. Swirl flow-forming body 1C may include, instead ofcylindrical body 91, plural cylindrical bodies having a smaller diameterthan cylindrical body 91, which are attached to end face 12, so thatswirl flow-forming body 1C can convey plural members at the same time.Cylindrical body 91 may have a shape other than the bellows shape.Cylindrical body 91 may gradually taper off from the end facing end face12 to the end facing a conveyed member.

Cylindrical body 91 may be attached to end surface 33 of radial flowforming body 3 according to the third embodiment.

5-6. Modification 6

The swirl flow-forming body or the radial flow-forming body according toeach of the above embodiments may be used to apply suction to, hold, andconvey a plate-like or sheet-like member such as a semiconductor waferor a glass substrate, instead of a food. Depending on a size of themember, plural swirl or radial flow-forming bodies that are attached toa plate-like frame may be used (for example, refer to FIGS. 10 and 11 ofpublished unexamined patent application number 2016-159405).

1, 1A, 1B, 1C, 2 . . . swirl flow-forming body, 3, 4 . . . radialflow-forming body, 11 . . . main body, 12 . . . end face, 13 . . .concave part, 14 . . . jetting port, 15 . . . inclined surface, 16 . . .guide groove, 17 . . . supply port, 18 . . . annular passage, 19 . . .communication path, 20 . . . supply path, 21 . . . annular wall, 22 . .. guide groove, 31 . . . main body, 32 . . . annular concave part, 33 .. . end face, 34 . . . opposing surface, 35 . . . inclined surface, 36 .. . guide groove, 37 . . . nozzle passage, 38 . . . introduction port,39 . . . introduction path, 40 . . . annular passage, 41 . . .communication passage, 42 . . . annular wall, 43, 51, 52, 53, 62, 63 . .. guide groove, 71 . . . protrusion, 81 . . . spacer, 91 . . .cylindrical body, 111 . . . inner-peripheral side surface

The invention claimed is:
 1. A suction device comprising: a cylindricalmain body; an end face formed on the main body; a concave part formed inthe end face, an opening edge of the concave part have a circular shape;a fluid flow-forming means for forming a fluid swirl flow in the concavepart by discharging fluid into the concave part, the fluid swirl flowgenerating negative pressure that applies suction to a member; and aplurality of linear guide grooves formed on the end face, each of theplurality of guide grooves being formed along a direction in which thefluid discharged into the concave part flows out of the concave part,the direction forming an angle of less than 45 degrees with respect to atangent line that passes through a contact point between the guidegroove and the opening edge of the concave part when viewed towards theend face.
 2. The suction device according to claim 1, wherein: the fluidflow-forming means is a fluid passage through which the fluid isdischarged into the concave part to cause the fluid swirl flow to beformed; and one of the plurality of guide grooves is formed on the endface, when viewed towards the end face, along a direction that forms anangle of approximately 45 degrees with respect to a direction in whichthe fluid passage extends.
 3. The suction device according to claim 1,wherein the guide groove is formed such that a cross-sectional area ofthe guide groove increases in proportion to a distance from the concavepart.
 4. The suction device according to claim 1, wherein the guidegroove is formed such that a cross-sectional area of the guide groovedecreases in proportion to a distance from the concave part.
 5. Thesuction device according to claim 1, further comprising a movementrestriction means provided on the end face, for restricting movementalong the end face of the member to which suction is applied by thenegative pressure.
 6. The suction device according to claim 5, whereinthe movement restriction means is a horn-shaped protrusion thatrestricts movement of the member by piercing the member.
 7. A suctiondevice comprising: a columnar main body; a concave part formed in asurface of the main body, an opening edge of the concave part having acircular shape; a fluid flow-forming means for forming a fluid swirlflow in the concave part by discharging fluid into the concave part, thefluid swirl flow generating negative pressure that applies suction to amember; an annular wall, provided so as to surround the concave part,that prevents the member from entering the concave part, the annularwall being formed such that a thickness of the annular wall graduallydecreases towards an end of the annular wall facing the member to besuctioned; and a plurality of linear guide grooves formed on an innerwall surface of the annular wall, each of the plurality of guide groovesbeing formed along a direction in which the fluid discharged into theconcave part flows out of the concave part, the inner wall surfacefacing a space in the annular wall, the space being connected to theconcave part to form one recess.
 8. A suction device comprising: acolumnar main body; a concave part formed in a surface of the main body,an opening edge of the concave part having a circular shape; a fluidflow-forming means for forming a fluid swirl flow in the concave part bydischarging fluid into the concave part, the fluid swirl flow generatingnegative pressure that applies suction to a member; an annular wall,provided so as to surround the concave part, that prevents the memberfrom entering the concave part, the annular wall being formed such thata thickness of the annular wall gradually decreases towards an end ofthe annular wall facing the member to be suctioned; and a plurality ofcurved guide grooves formed on an inner wall surface of the annularwall, each of the plurality of guide grooves being formed along adirection in which the fluid discharged into the concave part flows outof the concave part, the inner wall surface facing a space in theannular wall, the space being connected to the concave part to form onerecess, each of the plurality of guide grooves having a curved shapewhen viewed towards the opening edge of the concave part, a curvature ofa curve of each of the plurality of guide grooves being smaller than acurvature of the circular shape of the opening edge of the concave partwhen viewed towards the opening edge of the concave part.